Solid-liquid reaction processes



Nov. 25, 1952 n R. STANTON 2,619,496

-soLIp-LIQUD REACTION PROCESSES Filed Aug. 7, 1951 3 sheets-sheet 1 EQE@m z zz llll ` INVENToR. ROBERT STANTON BYX @4MM/ic( 14M H/S ATTORNEYS.

Nov. 25, R952 Filed Aug. '7, 1951 FLUID REACTANT SOL/D REACTANT R.STANTON SOLID-LIQUID REACTION PROCESSES REACTOR 5 Sheets-Sheet 2 EXCESS-FLU/D ROBERT STANTON BY MW@ fwk Nov. 25, T952 R. STANTON SOLID-LIQUIDREACTION PROCESSES 5 Sheets-Shaml 5 Filed Aug. 7, 1951 INVENTOR. ROBERTSTANTON H/s ATTORNEYS.

Patented Nov. 25, 1952 UNITED STATES PATENT OFFICE 13 Claims.

This invention relates to the reaction processes involving the reactionof lead-alkali metal alloy with a fluid alkylating agent, moreparticularly to such processes wherein the alloy reactant and the fluidreactant are brought together continuously, and it specifically relatesto such processes wherein molten alloy is solidified in coarsely dividedparticulate form and the so-formed alloy and the fluid reactant areintroduced into a reaction zone continuously; the reaction is conductedcontinuously under high speed agitation induced by fluid propulsionacting upon the solid reactant particles to impart high speed thereto,while the movement of the reactant particles is regulated so that thehigh speed solid particles undergo high energy collisions.

In the usual processes of reacting lead-sodium alloy with an alkylhalide, the alloy is prepared in a coarsely divided form by grinding orcrushing in a device of the ball-mill type.y The milled alloy is thencharged into a reactor through a suitable opening. Dangerous conditionsmay result from the exposure of the alloy to the atmosphere, or byleakage of tetraethyl lead vapor -from the reactor. In addition, theusual processes employ large reaction vessels involving relatively largereaction mixtures, and the reactions are relatively slow and difficultto regulate.

In accordance with the invention, it has been found that such processescan be conducted in a rapid and relatively safe, readily regulatedmanner, with improved yields. Small reaction mixtures are suitable. Thenew processes may be conducted in a fully continuous manner and give ahighly desirable product.

The objects achieved in accordance with the invention include theprovision of a process whereby the reaction of a solid lead-alkali metalalloy reactant and a iluid alkylating reactant may be conducted in acontinuous manner in a relatively small reaction zone and residenceperiod; provision of a process for the preparation of alkylated lead bythe preparation of a coarsely divided lead-alkali metal alloy andreacting it with alkyl halide in a continuous manner wherein relativelysmall reaction mixtures of the reactants are involved at any one time;the provision of a process for the preparation of tetraethyl lead by thepreparation of coarsely divided lead-sodium alloy and reacting it withethyl chloride in a continuous manner wherein relatively small reactionmixtures of the reactants are involved at any one time and wherein theparticle size of the coarsely divided alloy is reduced as the reactionproceeds; and other objects which will be apparent as details andembodiments of the invention are set forth hereinafter.

2 In accordance with the invention, a molten lead-alkali metal alloyreactant is formed into coarsely divided solid particles, mixed with analkylating reactant which is in the form of a uidv (desirably by firstsubjecting to elevated pressure of the fluid, then abruptly reducing thepressure and further mixing) under high speed agitation induced by uidpropulsion, and the movement of the reactants is regulated so that thesolid particles undergo high energy collisions; all under reactiontemperature and pressure conditions.

In an embodiment of the invention, the reaction mass moves through acurved path; and the influence of the centrifugal force will cause thelarger solid particles to travel near the outer periphery of the curvedpath, and the smaller or lighter particles to remain near the innerperiphery of the curved path. This favors chemical reaction, and therewill also be a reduction in size of the larger particles associated withthe high energy collisions in the system. As the reaction proceeds andthe solid reactant is reduced in particle size, the reactant and anyreaction products move to the inner periphery of the curved path. Themore finely divided reactant and any reaction product are removed fromthe inner periphery and then processed to recover reaction products,unconsumed reactants and byproducts or residues. When desirable,additional residence and reaction time may be provided for furtherreaction in a succeeding zone or chamber external to the circularreactor.

The process may be conducted in a fully continuous manner, in apartially continuous or intermittent manner, or in a batch type process.The fully continuous process is preferred for commercial operation.

In order to facilitate a clear understanding of the invention, referencemay be had to the accompanying drawings in which:

Figure 1 illustrates an arrangement of an apparatus, partiallydiagrammatical and partially in section, which may be employed forconducting the process of the invention, e. g., in the manufacture oftetraethyl lead.

Figure 2 represents a sketch of the process steps.

Figure 3 illustrates an alternative reaction chamber which may beemployed in connection with an arrangement of apparatus similar to thatin Figure l.

Figure 4 illustrates an alternative apparatus for subdividing the moltenalloy and solidifying it in coarsely divided form.

Figure 5 illustrates an alternative apparatus for preparing the moltenalloy.

In Figure 1, a fluid propulsion reaction chamber is represented by 5.This is in the form of a somewhat oval or elliptical loop, having a 180upper return bend 5A, a similar 180 lower return bend 5B, and straightvertical connecting pipes 5C and 5D. This chamber is in the form of anendless conduit of uniform circular cross section.

A molten alloy supply vessel IDI is positioned so that alloy may bepoured therefrom onto a perforated member |62, from which it drops inthe form of droplets within a stack |03 into a cooling liquid such aslight mineral oil contained in vessel |05. The alloy particles partiallysolidify by cooling in contact with a rising current of gas, and arechilled in the mineral oil. The temperature of the melt, the distance offall through gas, the character of the cooling medium, and the likevariables are preferably adjusted to provide alloy particles coated witha thin carbonized oil-protective lm. Burners |84 are provided at thelower end of the stack for supplying combustion gases (a nonoxidizingatmosphere) in the stack. Other gases, or even air, could be circulatedtherein; and passed out of the tap. The vessel |05 is provided withagitating means |06 for keeping the alloy particles suspended in theliquid. A hydraulic ejector |01, energized by a high-pressure stream ofcooling fluid, is arranged to continuously feed portions of the slurryfrom vessel |05 into transfer pipe |03 which delivers it intocompartment |09 of the elevated vessel I I0. The liquid level in thiscompartment is maintained sufficiently high to constitute a seal againstbackward flow of toxic vapors from the reaction zone. This vessel isdivided vertically by the weir plate I I I. The alloy particles settledue to the relatively low velocity in the compartment, and fluid overowsthe weir plate into the discharge compartment I I2. From there, thefiuid flows by gravity through pipe I I3 into surge tank I Ill. Liquidfrom the surge tank constantly passes through the cooling vessel IE5,under a constant level or pressure head, either directly through a pipeI I5 (or preferably through pipe I I5 and purication'vessels I 22containing boiling aqueous hydrochloric acid or the like and |23containing aqueous caustic or the like neutralizing agent, for removingalkylated lead, as shown). Excess fluid overflows through line ||6 intoreceiver II'I; from which it is delivered under elevated pressurethrough pump IIS to activate the hydraulic ejector I0?.

The alloy may be made up and melted at ground level and then elevated tothe top of the stack or shot tower, e. g., by hoisting and tilting, orby pumping, or by a gas-lift (in which hydrocarbon gas may be used andignited at the discharge to maintain the alloy in molten condition).

The vessel I I0 is provided with a vertically inclined continuouschain-type converter I |5,having one or more perforated blades |20attached to the traveling chain in such a manner as to drag the alloyupward along the lower inclined surface housing, and permit fluid todrain back into the compartment |09. By this means, or other equivalentelevating means, substantially huid-free coarsely divided alloy may bedischarged continuously from the spout at the upper end of the conveyorinto the conical hopper I GI. rThis conical feed hopper is closed at thetop by the removable cover 2, communicates at its lower end with theconstant volume feed mechanism 3, which in turn communicates with thethroat portion of the downwardly inclined injector (Venturi) feed tube4.. This feed tub-e is arranged to discharge substantially tangentiallyinto the lower curved portion of the chamber 5. t is desirable toarrange the feed tube to saturate the solid reactant with liquidreactant or propellant under elevated pressure and to abruptly reducethe pressure on the saturated solid reactant when it is discharged fromthe injector.

It is desirable to use an injector provided with a high-velocity nozzlefor introducing fluid at elevated pressure into the plenum chamberWherein a negative or reduced pressure is employed, an inlet port forfeeding coarsely divided alloy into the plenum chamber, a convergentnozzle or throat portion joining the plenum chamber to a saturating tubeportion, which tube leads into an abrupt expansion tube portion. Theoutlet end of the expansion tube portion may be provided with anaxial-flow type valve closure provided with suitable stuffing box andadjusting means such as screw threads for regulating its distance fromthe tube. It is preferred to maintain a vacuum of about 10" Hg in theplenum chamber. However, this may be varied depending on the materialhandled. If ethyl chloride vapor is introduced into such an injector ata pressure of pounds per square inch gauge, any pressure within therange of 0 up to 50 pounds per square inch gauge (at which point thereis a sharp change to back-flow) may be maintained in the saturating tubeportion. This saturating tube portion may be constructed so that itscross-sectional area is uniform throughout its length, or it may bevaried, e. g., slightly divergent toward the exit end; however, thecross-sectional area at any point thereof should not exceed the largestcrosssectional area of the throat portion. The throat portion ispreferably constructed with a 30 taper.

By this means, the reaction mixture may be abruptly shocked and passeddirectly into the circular path reaction chamber, thus facilitatingrapid chemical reaction.

The chamber 5 is provided with a plurality of substantially tangentiallydisposed high velocity fluid jets 1, which are in communication with thefluid reactant supply tank I4 through pump I6, heater Il, and chamberI8. Tank I4 is equipped with a feed line I5.

An exhaust line 8 -communicates with the chamber 5 at the innerperiphery and near the point where the upper semi-circular member 5Ajoints with the vertical descending member 5D, thereof. The other end ofthe exhaust pipe 8 communicates substantially tangentially with the sideof the low Velocity cyclone separator 9. This separator is provided withan annular arrangement of downwardly ydirected spray nozzles I0,positioned above the point of communication of the exhaust line 8. Thetop of the cyclone separator is equipped with -a partial condenser I2,and also communicates serially with the final condenser I3, which nalcondenser communicates with the fluid reactant feed tank I4.

The lower `end of the cyclone separator 9 communicates with a closedchamber II which is equipped with a strainer I9. The closed container IImay provide the additional reaction period for the reactants when it isdesired as mentioned above. The strainer` I9 communicates with thestripping column 20 (which may be or" the multiple tray, or packed towertype). The column 20 communicates at its lower end with the reboiler 2|.The reboiler 2| is equipped with a product removal seal pipe 22.

The chamber I| communicates with an upwardly inclined helicalribbon-type 'conveyol` 25, which conveyor in turn communicates with astorage vessel 25. The conveyor 25 is equipped with an annular heatingjacket 21 at the upper end thereof. Conveyor 25 also communicates with a`vapor line 28, at a point below the heating jacket 21, and it alsocommunicates with a backwash line 39, at a point below the vapor line28.

A solvent supply tank 24, which is equipped with a feed inlet (notshown), communicates through pump 29 with line 30. Line 30 alsocommunicates with the annular spray nozzles I through line 3|. Tank 24also communicates with the upper partnof the strip-ping column 20through line 32. The upper part of stripping column 2li communicateswith condenser 23 through line 28, and this condenser in. turncommunicates with tank 24.

Figure 2 schematically illustrates the process. A solid reactant isprepared in shot or the like coarsely divided form and is broughttogether with fluid reactant in the reactor, under reacti-on temperatureand pressure conditions, with high speed fluid propulsion agitation.Reaction, attrition of solid particles and classification of solidparticles occur in the reactor. As the solid reactant is reduced inparticle size through reaction and attrition, the reaction products andunconsumed reactants are passed from the reactor to a separator whereinadditional reaction is provided, if desired, and the desired product isseparated. In addition, unconsumed fluid reactant may be separatelyrecovered, and unconsumed solid reactant collected as or in a residue.

Figure 3 illustrates an alternative type :of reaction chamber. Asubstantially cylindrical chamber 43 communicates with solid reactantfeed hopper 40 (which is equipped with a cover, not shown) through theVenturi feed line 4|. The Venturi line also communicates with fluid line42. Fluid jets 44 communicate with chamber 43 at the outer circumferencethereof, and are directed tangentially to a circle of somewhat smallerradius than the outer radius of the chamber The jets 44 and line 42communicate with uid jet lines 45 and 46. The central portion of chambery43 communicates with chamber 48 and line 50. Chamber 43 is providedwith a flange 41 which protrudes above the lower surface of chamber 43.Line 50 is of smaller diameter than chamber 48, and the lower end ofline 50 is set -somewhat below the iiange 41. Line `50 may be connectedwith a series of condensers at the upper end thereof, 5|. Chamber 48 maybe connected with -chamber of Figure 1 through throat 49.

In the apparatus of Figure 4, a vessel (like vessel |535 of Figure l) isprovided with a vertically arranged shaft |21 (supported by suitablebearings) carrying a horizontal disc |25, which disc is positionedslightly below the level of a body of the cooling fluid |26, and alsowith agitator blades |28 set in the body of cooling uid. The shaft, discand agitator are rapidly rotated (by suitable means), and the iiuidlevel builds up slightly above the outer edge of the disc, the uppersurface of the disc remaining relatively dry. Preferably the uppersurface of the disc is in a yraised conical form. Molten alloy is passedfrom the spout |24 at a uniform rate onto the inner portion or `area ofthe rapidly spinning dis-c, and is thrown from the edge of the disc inthe form of a shower or spray which is quickly quenched and solidifiedupon entering the body of cooling fluid. If the upper surface of thedisc is in the preferred raised conical form, it will impart a downwardthrust to the alloy droplets as they leave the disc. The agitator |28serves to main- 61' tain the coarsely divided alloy in suspension in theuid and also to break up any filaments or rod-like pieces of the alloy.

Figure 5 illustrates a convenient molten alloy preparing apparatus,containing a rotating barrel member |29 provided with suitable rotatingmeans and set in a housing member |30 provided with heating means (notshown). The rotating barrel member is provided with spiral vanelikelmembers |3| which facilitate the movement of incompletely molten alloymaterial toward the spout end thereof. The cover |32 (rotatably or xedlyattached to hinged supporting member |33) may be opened and pieces oflead and sodium introduced to charge the apparatus. The apparatus isprovided with means for adjusting the angle of tilt, and thus regulatethe flow of alloy from the spout. The member |33 may be arranged to tiltor open upward, or horizontally if desired.

Other types of curved path reaction chambers in which turbulent flow oragitation and classification may occur are suitable. The cross sectionneed not be tubular or cylindrical. Spiral, helical, reversed curve,annular, multistage, and the like shaped reaction vessels may beemployed. Combinations of tubular and vortex type chambers may be used.

If desired, fluid propulsion jets may be positioned at the outer part ornearer the inner part of the reaction chamber '(cross section) so as toincrease, decrease or otherwise modify turbulent ow in the chamber, e.g., to favor or modify double inverse helical flow, spiral flow,transverse eddy currents, or the like therein.

In one embodiment, the process of the invention may be applied to themanufacture of tetraethyl lead by the reaction of lead-sodium alloy andethyl chloride. 'Ietraethyl lead is of great commercial importance andit is consumed in large quantities as an ingredient in gasoline and thelike internal combustionengine fuels.

Various methods have been proposed heretofore for the manufacture oftetraethyl lead, e. g., from lead-sodium alloy and ethyl chloride. Onetype involves charging a batch of the (about lead-10% sodium) alloy intoa reaction vessel and treating this with a batch or a continuous orintermittent stream of ethyl chloride. The reaction vessel may be in theform of an autoclave equipped with a rotary stirrer, or a rotatingball-mill, or similar batch type apparatus. These prior processes aresubject to many drawbacks. They involve long reaction periods and leavemuch to be desired as to yields. The alloy particles and the sodiumchloride by-products of the reaction tend to agglomerate into largerlumps, and thus a substantial amount of the alloy is shielded fromcontact with the ethyl chloride reactants. In addition, the agglomeratedmass retains a substantial amount of the tetraethyl lead product, andthe recovery of the product therefrom is tedious and wasteful.

There is considerable hazard involved in large reaction batch operationscontaining a large charge of the alloy. The reaction may occur withexplosive violence. If moisture should happen to come in contact withthe alloy, an explosion may occur. Where the process is conducted underpressure, there is considerable health hazard from any of the highlytoxic tetraethyl lead vapors which might escape from'the various valves,stuing boxes and mechanical closures involved in batch type reactionvessels.

In accordance with the invention, it has been foundfthat theY abovedrawbacks may be overcome and the tetraethyl lead produced in acommercially more advantageous manner.

For the preparation of tetraethyl lead, using the apparatus illustratedin Figure 1, lead metal and sodium metal may be introduced and molten invessel II. The molten alloy may be passed through the perforated member|02, to form droplets which are substantially solidified by passingthrough substantially inert gases and then quickly chilled or cooled bypassing into kerosene or the likev light petroleum oil cooling huid in'vessel |05, to give very brittle particles in the form of shot having aprotective film coating; which particles are especially reactive whenprocessed in the reaction chamber as discussed below. The shot iscontinuously tran.,- ferred to compartment |09 of vessel I lil and thento the hopper IUI. 'I'he fluid supply tank Ill is lled with ethylchloride. thyl chloride is maintained in the chamber I8 at a pressure ofabout 100 pounds per square inch gauge and a temperature of about 180 F.The alloy is fed into the reaction chamber 5 by means of the feedermechanism 3 and the injector 4 (including the ethyl chloride jet fromline S). Ethyl chloride is also injected through jets l.

Both the amount of the ethyl chloride and that of the lead used are inexcess of the stoichiometric requirements. Preferably, the amount of Cethyl chloride is chosen so as to impart an average linear velocity ofabout 10 to 100 feet per second within the reaction chamber, i. e.,turbulent ow with transverse eddy currents. This causes vigorousagitation therein, and associethyl chloride and the alloy occurs rapidlyat lent fiow movement imparted to the particles of 1 the fluidpropellant which is tangentially introluced from the outer periphery ofthis region insures that the reacting surface is maintained in mostreactive form by removal of any shielding coating and by the attritionof the alloy particles associated with the high energy collisions in thereaction chamber and chemical erosion. The by-product sodium chloridedoes not lump up or occlude unreacted alloy or finished reactionproduct, and it is maintained in a nely divided state. The alloyparticles may travel around the reaction chamber one or more times inbeing reduced to a substantially finely divided form.

The reaction mixture of unconsumed reactants, reaction products andresidue travels near the inner periphery of the chamber 5, and iswithdrawn through exhaust line 8. This withdrawn portion is thenprocessed to recover tetraethyl lead, unconsumed ethyl chloride, and aresidue which may contain recoverable lead. In

. tained without giving unduly high pressures.

one embodiment, the withdrawn reaction mixture is passed to the lowpressure cyclone separator 9 and sprayed with acetone (from tank 24through the spray nozzles I0). The ethyl chloride vapor undergoes ascrubbing due to the effect of the partial condenser I2, and then passesupward to the condenser I3, where it is condensed and returned to theethyl chloride tank I4. Additional make-up ethyl chloride may beintroduced through line I5, if necessary.

The acetone solution of tetraethyl lead plus the solid residue passes tochamber I I. The acetone solution, removed therefrom through strainerI9, passes to the stripping column 20. The acetone is vapor-ized, andthe vapor passes to condenser 23, is condensed, and then passes toacetone solvent. tank 24. Finished tetraethyl lead is removed throughline 22.

The solid residue passes from chamber I I to the conveyor 25 wherein itis back-washed with acetone, supplied through line 30. It is then heatedat a temperature of about 200 F. to expel acetone vapors and impart afinal drying effect to the spent alloy. The acetone vapor passes up tothe condenser 23, is liquied, and then passes to tank 24. rlhe spentalloy passes to chamber 26. It may be removed and processed to recoverany lead therein, in accordance with known procedures.

The reaction chamber 5 may be supplied with a temperature regulatingjacket, or set in a temperature regulating bath, in order to regulatethe temperature thereof. Where the ethyl chloride is present as a vaporin the reaction chamber, the expansion of the ethyl chloride leaving thejets is accompanied by a refrigerating effect. This may be adjusted soas to control the temperature of the reaction system, i. e., absorb theheat evolved by the exothermic chemical reaction in the formation of thetetraethyl lead.

The acetone spray in the separator serves to strip tetraethyl lead fromthe vapors as well as to help settle the spent alloy particles andbyproduct, sodium chloride. The effect of the partial condenser I 2 isto further strip tetraethyl lead from the vapors of ethyl chloride.

It has been found that the recovered and recirculated ethyl chloridetends to give a higher yield of tetraethyl lead, than does fresh ethylchloride. It is thought that some material carried over in the recoveredethyl4 chloride has a beneficial effect on the reaction.

rl'he process may be carried out in apparatus which includes heatexchange devices; e. g., to use the heat contained in the ethyl chloridevapor to preheat fresh ethyl chloride liquid.

The reactant in fluid form may contain a diluent or solvent and shouldbe readily owable in order that sufficient propulsion may be ob- If thereactant is in the form of a liquid, it is preferable that the viscositythereof should not be higher than that of an about S. A. E. 50 motorlubricating oil at ordinary room temperatures.

The reaction may be conducted with the iluid reactant in either thevapor phase or the liquid phase.

In an illustrative vapor phase operation, a Figure 1 type of apparatusis used with a reaction chamber of 1.45 sq. inch inner cross-sectionalarea, the top and bottom turns of a radius of curvature of 6 inches, andthe vertical connectors 26 inches in length; the saturating tube portionof the injector is of the same inner crosssectional area as the reactionchamber, and ve 'acreage trogen may be employed vas the fluid propulsionagent. In this case, the amount of the organic halide would be aboutsufcient to complete the chemical reaction. The fluid reactant could beintroduced in one set of one or more jets; and the fluid propulsionagent, e. g., nitrogen in another set of one or more jets.

,If desired, the above-described product separation and recovery systemmay be replaced by Vapor Phase Liquid Phase Duration of Run 1 hour 30minutes. Weight of Alloy Charg 145 lbs 24 lbs. v Composition of Alloy--Na, 90% Pb 10% Na, 90% Pb. Reactor Temperature. 135 F 125 F.

Pressure at Reactor Inlets Pressure at Reactor Outlet Total EthylChloride Charged Rat Chloride Feed Tetraethyl Lead Produced Yield Basedon Sodium Consumed Ethyl Chloride Consumed Yield Eiiiciency Based onEthyl Chloride. Average Size of Alloy Feed Average Size of Lead Residue.Velocity at Reactor Outlet 10 mesh.

microns.

10 F. P. S.

l Pounds per square inch guage. 2 Feet per second average linear massvelocity.

Iihere is also a tendency for a caking or coating of the balls (to formlumps) in the mill, and this will similarly isolate the two reactantsfrom each other and occlude the reaction product so as to make recoverythereof difficult.

In the normal operation of the above-described process, there will be noappreciable health hazards from the escape of tetraethyl lead vapors.The high pressure part of the reaction system, wherein tetraethyl leadoccurs, is completely closed. If desired, the pumping units may becompletely submerged Within the corresponding tanks, in order to avoidpossible leakage of liquid from any stuffing boxes or rotary shaftseals. If desired, the condensing units and tanks may be set at asuitable height relative to the remainder of the apparatus, so that thestatic pressure of the liquid will be sufficient for movement of theliquid without the use of pumps.

Other proportions of lead to alkali may be used in the alloy, e. g.,containing mor-e than about 12.5% sodium. The alloy may be made up fromone or more alkali metals, e. g., mixtures of alkali metals may be used.Other organic halides may be used, e. g., ethyl bromide, and othersolvents than acetone may be used; as the art will readily appreciate inview of the above descriptions. A higher boiling fraction of gasolinemay be used as a solvent; and the solvent solution of the tetraethyllead could be directly blended with gasoline to give a desired motorfuel.

If desired, known promoters or catalysts may7 be included in thereaction mixture. Ferrie chloride or anhydrous aluminum chloridemay besuspended in an inert vehicle, such as a petroleum distillate, andintroduced in controlled amounts into the reaction chamber at aconvenient point.

If desired, the ethyl chloride vaporizing and condensing apparatus maybe replaced by a mechanical apparatus for developing the requiredpressure. Alternatively, an inert gas such as niconventional quenchingand steam distillation methods. For instance, the mixture of tetraethyllead and spent alloy can be discharged from the lower end of the cycloneseparator 9 into a chamber containing a plurality of steam jets and then'to a second cyclone separator, wherein the spent alloy particles areseparated by a gravity effect, while the steam and tetraethyl lead vaporare removed/condensed, and the two immiscible liquids separately removedfrom the condensate. l

f- Where the alternative reaction chamber of Figure 3 is employed, it ispreferred that the fluid reactant be present in the form of a vapor,with or vwithout additional or diluent gas.

In View of the foregoing disclosures, the art will appreciate that othermethods may be used to solidify molten reactant in coarsely dividedsolid form and contact it with the reactant in fluid form so as toachieve the benefits of high speed fluid propulsion, while the reactionis in progress, together with maintaining the solid reactant in activecontact with the fluid reactant; e. g., by a shearing or cleaning actionto remove any shielding coating, or by an attrition of the solidparticles to present clean solid reactant surface; and classifying orseparating substantially finely divided material from the reaction zone.In View of the foregoing disclosures,` variations and modifications ofapplications of the invention will be apparent to those skilled in theart; and the invention contemplates all such other methods, variationsand modications except as do' not come within the appended claims.

This application is a continuation-in-part of my copending applicationSerial No. 28,614 filed May 22, 1948.

Iolaim:

1. A process for the preparation of alkylated lead which comprisesforming molten lead alkali metal alloy into substantially solidifiedcoarsely divided hot particles in substantially round form and quicklycooling said particles in light petroleum oil whereby a protective lmcoating is formed on said particles and the metal therein is Verybrittle, mixing said coated particles with alkyl chloride to give amixture which tends to provide a shielding coating on said solidinterferring with the eiiicient reactive contact of the alkyl chloridewith the alloy, mixing these reactants under high spe-ed agitationinduced by fluid propulsion while the movement of said mixture isconfined to a substantially closed curved path, under reactiontemperature and pressure conditions, whereby the chemical reaction isintensified and fresh reactant surfaces are maintained, and separatelyrecovering reaction products from the process.

2. A process of claim 1 wherein the solid particles suspended in thelight petroleum oil are substantially separated from the oil and thenmixed with the iiuid reactant and the path of movement of the reactantmixture is a substantially elliptical path and the reactants are subjectto greatest centrifugal compression substantially at one end of saidsubstantially elliptical path of movement and the duid propellant isintroduced tangentially from the outer periphery of this substantiallyelliptical path region of greatest compression.

3. A process of claim 2 which is carried out in a continuous manner andwherein the suspension of solid particles in the light petroleum oil isflowed to the zone of separation of the solid therefrom, the alloy is inthe form of about 4 mesh substantially spherical particles and theelliptical path is substantially vertical with the region of greatestcompression at the lower end thereof.

4. The process of claim 3 wherein the reaction mixture contains acatalyst and the alkyl chloride reactant is in the form of a liquid.

5. A process of claim 4 wherein the alkyl chloride is ethyl chloride.

6. A process of claim 5 wherein the Vhigh speed agitation isinduced byinert gas propulsion.

7. A process of claim 5 wherein the removed more nely divided portion ofthe reaction mixture is contacted with a solvent for tetraethyl lead,and a solution of tetraethyl lead in said solvent is separated fromunreacted ethyl chloride and from the residue.

8. A process of claim 3 wherein the alkyl chloride reactant is in theform of a vapor.

9. A process `of claim 8 wherein the alkyl chloride is Yethyl chloride.

10. A process of claim 9 wherein the removed more nely divided portionof the reaction mixture is contacted with a solvent for tetraethyl lead,and a solution of tetraethyl lead in said solvent is separated fromunreacted ethyl chloride and from the residue.

11. A process of claim 9 wherein the reaction mixture contains acatalyst and the high speed agitation is induced by inert gaspropulsion.

12. A process of claim 11 wherein the reactant mixture moves with anaverage linear velocity in the range of 10 to 100 feet per second.

13. A process of claim 12 wherein the solid revactant in coarselydivided form is mixed with the fluid reactant under elevated pressureand then the pressure is reduced abruptly and then the reactants aremixed under the high speed agitation.

ROBERT STANTON'.

REFERENCES CITED 'llrc following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,148,194 Seifert et al July 27,1915 1,962,173 Calcott et al June 12, 1934 1,974,167 Voorhees Sept. 18,1934 2,029,301 Bake Feb. 4, 1936 2,043,224 Amick et al June 9, 19362,109,005 Bake Feb. 22, 1938 2,310,806 Nourse Feb. 9, 1943 2,351,091 BarJune 13, 1944 2,391,723 Mann Dec. 25, 1945

1. A PROCESS FOR THE PREPARATION OF ALKYLATED LEAD WHICH COMPRISESFORMING MOLTEN LEAD ALKALI METAL ALLOY INTO SUBSTANTIALLY SOLIDIFIEDCOARSELY DIVIDED HOT PARTICLES IN SUBSTANTIALLY ROUND FORM AND QUICKLYCOOLING SAID PARTICLES IN LIGHT PETROLEUM OIL WHEREBY A PROTECTIVE FILMCOATING IS FORMED ON SAID PARTICLES AND THE METAL THEREIN IS VERYBRITTLE, MIXING SAID COATED PARTICLES WITH ALKYL CHLORIDE TO GIVE AMIXTURE WHICH TENDS TO PROVIDE A SHIELDING COATING ON SAID SOLIDINTERFERRING WITH THE EFFICIENT REACTIVE CONTACT OF THE ALKYL CHLORIDEWITH THE ALLOY, MIXING THESE REACTANTS UNDER HIGH SPEED AGITATIONINDUCED BY FLUID PROPULSION WHILE THE MOVEMENT OF SAID MIXTURE ISCONFINED TO A SUBSTANTIALLY CLOSED CURVED